In article ,
says...
I want to make a hole for a vent in the wall of a brick house.
On the inside I see wood planks, on the outside there's brick. I have no
idea if there's something in between.

is there anything I should be aware of, anything I could do wrong while
cutting the hole?

Hidden studs, wiring, and plumbing.

there are circular blade kits used for making these kinds of holes, that's
what I will use

Hmmm. Either an awful small vent, or a rather expensive
tool for a one-time use.
--
Mark

The truth as I perceive it to be.
Your perception may be different.

Triple Z is spam control.